A method of this type is discussed in German patent document DE 10 2004 009 651 A1. In this method, which especially may be used for welding together aluminum and copper, a laser beam having a lateral offset of a few tenths of a millimeter to a joining zone is inserted into the aluminum that has a lower melting zone. In such a welding offset in the direction towards the aluminum, the copper is melted only partially directly by the laser beam but also indirectly by the aluminum melt. In the method, relatively high strength factors are able to be achieved, in spite of the use of different types of metals. The problem in this context is particularly the appearance of the so-called intermetallic phase in the joining zone by the mixing of the two liquified materials in the molten state. Such an intermetallic phase is characterized by hard and brittle regions, which lead to a decrease in the strength factors. Nevertheless, even in the known method, in the region of the joining zone, a complete melting of the aluminum takes place as well as at least a partial melting of the copper.
In addition, in DE 103 59 564 A1, of this Applicant, in the connecting region of two components, having a different melting temperature, by melting the component having a lower melting temperature and a corresponding forming of the two components after the hardening of the melt, one may develop a form-locking connection in which the one component having the lower melting temperature forms a sort of rivet, for example, which encompasses a recess in the component having the higher melting temperature with form locking.